Fellow: Marni Shear, DO, Children's Hospital Los Angeles/University of Southern California, Keck School of Medicine
Article: Shein, S.L., Slain, K., Schlurmann, N.M., Speicher, R., & Rotta, A.T. (2017). Hyponatremia and Hypotonic Intravenous Fluids Are Associated With Unfavorable Outcomes of Bronchiolitis Admissions. Hospital Pediatrics. 7(5), 263-270.
Summary: Shein, et al. performed a retrospective, single-center study that analyzed data from 1557 hospitalized pediatric patients with a diagnosis of bronchiolitis to assess whether there was an association between early hyponatremia and unfavorable clinical outcomes, late hyponatremia and unfavorable clinical outcomes, and whether intravenous fluid (IVF) tonicity was associated with any of these findings. The study found an association between lowest blood sodium level measured during the first 4 days of admission and increased length of stay (LOS), further reinforcing findings of previous studies. The authors also demonstrated that hyponatremia later in admission was associated with increased LOS as well as increased need for mechanical ventilation. Additionally, the study found associations between increased LOS and need for mechanical ventilation with administration of severely hypotonic IVF (sodium <70mEq/L) suggesting that IVF selection may be a modifiable risk factor for clinical outcomes of patients admitted for bronchiolitis.
What are the key strengths of the article?
This study reinforces the findings of previous studies that identify associations between unfavorable clinical outcomes among patients with bronchiolitis that have hyponatremia around the time of admission and expands on these studies by evaluating the effects of hyponatremia when identified later in admission. It describes a larger cohort of patients than previously studied and also describes associations between the use of severely hypotonic IVFs and poor clinical outcomes among patients admitted with bronchiolitis, thus suggesting a possible modifiable risk factor for more severe disease.
Are there any limitations or flaws in the article?
One of the most significant limitations in this study was the availability of birth year of each patient, but not birth date. As such, data could not be stratified or analyzed by the age of the child in months during the first year of life. Additionally, the database used to perform this study did not include patient comorbidities that might serve as concomitant risk factors for poor clinical outcomes. Other limitations include the retrospective design of this study, which limits the ability to assess causality, and exclusion of patients that did not require a lab draw on a specific day or did not receive IVF on a specific day, thus limiting the sample size that could be analyzed each day. Defining hyponatremia as blood sodium <135mEq/L was another limitation, as this may not be considered hyponatremia by some institutional standards and could result in over-diagnosis of hyponatremia. Finally, the stratification of IVF administration as either sodium <70mEq/L or >70mEq/L was somewhat limiting, in that it does not provide data as to whether 0.45% NS, a form of hypotonic solution that falls into the sodium >70mEq/L category, is associated with development of hyponatremia in this patient population.
What is the major takeaway message?
This study demonstrates associations between both early and late hyponatremia and unfavorable clinical outcomes, including increased LOS and need for mechanical ventilation for patients admitted with bronchiolitis. It also describes an association between administration of severely hypotonic IVF and unfavorable clinical outcomes, suggestive of a possible modifiable risk factor for development of hyponatremia.
Describe how this article should impact our practice:
This study offers new evidence of unfavorable clinical outcomes in association with hyponatremia and the use of severely hypotonic IVF among patients with bronchiolitis, which will hopefully discourage the use of severely hypotonic IVF in this patient population. As this study does not stratify outcomes based on the use of 0.45% NS and 0.9% NS, however, this may limit the impact to the practice of individuals who have already moved towards using IVF with sodium >70mEq/L.
Article: Shein, S.L., Slain, K., Schlurmann, N.M., Speicher, R., & Rotta, A.T. (2017). Hyponatremia and Hypotonic Intravenous Fluids Are Associated With Unfavorable Outcomes of Bronchiolitis Admissions. Hospital Pediatrics. 7(5), 263-270.
Summary: Shein, et al. performed a retrospective, single-center study that analyzed data from 1557 hospitalized pediatric patients with a diagnosis of bronchiolitis to assess whether there was an association between early hyponatremia and unfavorable clinical outcomes, late hyponatremia and unfavorable clinical outcomes, and whether intravenous fluid (IVF) tonicity was associated with any of these findings. The study found an association between lowest blood sodium level measured during the first 4 days of admission and increased length of stay (LOS), further reinforcing findings of previous studies. The authors also demonstrated that hyponatremia later in admission was associated with increased LOS as well as increased need for mechanical ventilation. Additionally, the study found associations between increased LOS and need for mechanical ventilation with administration of severely hypotonic IVF (sodium <70mEq/L) suggesting that IVF selection may be a modifiable risk factor for clinical outcomes of patients admitted for bronchiolitis.
What are the key strengths of the article?
This study reinforces the findings of previous studies that identify associations between unfavorable clinical outcomes among patients with bronchiolitis that have hyponatremia around the time of admission and expands on these studies by evaluating the effects of hyponatremia when identified later in admission. It describes a larger cohort of patients than previously studied and also describes associations between the use of severely hypotonic IVFs and poor clinical outcomes among patients admitted with bronchiolitis, thus suggesting a possible modifiable risk factor for more severe disease.
Are there any limitations or flaws in the article?
One of the most significant limitations in this study was the availability of birth year of each patient, but not birth date. As such, data could not be stratified or analyzed by the age of the child in months during the first year of life. Additionally, the database used to perform this study did not include patient comorbidities that might serve as concomitant risk factors for poor clinical outcomes. Other limitations include the retrospective design of this study, which limits the ability to assess causality, and exclusion of patients that did not require a lab draw on a specific day or did not receive IVF on a specific day, thus limiting the sample size that could be analyzed each day. Defining hyponatremia as blood sodium <135mEq/L was another limitation, as this may not be considered hyponatremia by some institutional standards and could result in over-diagnosis of hyponatremia. Finally, the stratification of IVF administration as either sodium <70mEq/L or >70mEq/L was somewhat limiting, in that it does not provide data as to whether 0.45% NS, a form of hypotonic solution that falls into the sodium >70mEq/L category, is associated with development of hyponatremia in this patient population.
What is the major takeaway message?
This study demonstrates associations between both early and late hyponatremia and unfavorable clinical outcomes, including increased LOS and need for mechanical ventilation for patients admitted with bronchiolitis. It also describes an association between administration of severely hypotonic IVF and unfavorable clinical outcomes, suggestive of a possible modifiable risk factor for development of hyponatremia.
Describe how this article should impact our practice:
This study offers new evidence of unfavorable clinical outcomes in association with hyponatremia and the use of severely hypotonic IVF among patients with bronchiolitis, which will hopefully discourage the use of severely hypotonic IVF in this patient population. As this study does not stratify outcomes based on the use of 0.45% NS and 0.9% NS, however, this may limit the impact to the practice of individuals who have already moved towards using IVF with sodium >70mEq/L.